Which European country is spotted with numerous small concrete bunkers?

Albania

Norway

Serbia

Greece

During the forty-year lead­er­ship of Enver Hoxha of the People's So­cial­ist Republic of Albania, over 700,000 bunkers were built in the country – one for every four in­hab­i­tants. The bunkers are still seen ev­ery­where in Albania. Most are now dere­lic­t, but some have been reused for a variety of purposes in­clud­ing res­i­den­tial dwellings, cafés, store­hous­es and shelters for animals.